Answer:
18 minutes
Step-by-step explanation:
Given that the time (T) varies directly as the number of spectators (S) and varies inversely as number of open exits (E).
Hence:
T ∝ S; T ∝ 1 / E
Let k be the constant of proportionality. This gives:
T = kS / E
when T = 12 minutes, S = 20000, E = 20. Hence:
12 = k(20000) / 20
20000k = 240
k = 12 / 1000
This gives:
T =
When S = 36000, E = 24, we are to calculate the time (T):
T = 18 minutes